Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 443 [Rate centres in NPA 443] [Dial plan for NPA 443]

NXX: 251

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-251 A Catonsville MD BLTQMD010MD  082H LOCAL ACCESS LLC - MD 238      
443-251 0 Catonsville MD   876D ONVOY, LLC - MD 238   2014-09-05   
443-251 1 Catonsville MD   082H LOCAL ACCESS LLC - MD 238   2013-10-11   
443-251 2 Catonsville MD   318J COMCAST IP PHONE LLC 238   2014-02-12   
443-251 3 Catonsville MD   876D ONVOY, LLC - MD 238   2014-12-31   
443-251 4 Catonsville MD   876D ONVOY, LLC - MD 238   2014-12-31   
443-251 5 Catonsville MD   318J COMCAST IP PHONE LLC 238   2014-08-21   
443-251 6 Catonsville MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC DBA T-MOBILE USA 238   2014-12-13   
443-251 7 Catonsville MD   508J CENTURYLINK COMMUNICATIONS LLC 238   2014-04-02   
443-251 8 Catonsville MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC DBA T-MOBILE USA 238   2014-10-10   
443-251 9 Catonsville MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC DBA T-MOBILE USA 238   2013-12-09   

Last updated: Fri, 01 Jul 2022 02:53:40 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.